detonation and how to get rid of it?

[Vovan]

anyone knows?

[JimX]

In order of easiest to hardest (assuming stock car)

Increase the octane of your fuel. Back your timing off. Reduce your boost. Richen up your fuel mixtures.

[Vovan]

What does "Back your timing off" mean?

[fireblade]

Install a water injection system

[JimX]

On your exhaust cam gear there is a metal thing with 3 bolts on it. Loosen the 3 bolts and turn the unit a couple of mm anticlockwise. Tighten the bolts back up again.

[Mildman]

I did exactly this last night, so can recommend to Vovan. I had a different problem and adjusted that wheel to full advance. And then on progressive road tests kept backing it off until I didnt hear any pinging. It's pretty easy and there is not much you can f**k up.

[wrxhoon]

thats the crank angle sensor that adjusts the timing.

do do it right u need a timing light so u can adjust it to specs .

trial end error like mildman did is 2nd best option but carefull cause if u advance to much u risk detonation and maybe a blown piston to little and it will be gutless.

the specs are .

rb 25 15deg+/-2 @650rpm +/-50 and rb26 21deg =/-1 @950 rpm +-50 .

generaly speaking u can advance it a little more like 2-5 deg without it pinging but next time u get fuel ( octane varies ) it may ping so be alert !! pinging is risky .

[Mildman]

At least it is fairly easy to hear the pining, (I guess this depends on the amount of mods to your engine).

But you are correct wrxhoon doing things to specs is safer...but with trial and error you can find a little bit more advance than the specs - which in my case has lead to a reduction in exhaust gas temperature.

(I was doing the changes as my exhaust manifold was glowing red hot after driving...indicating something not right with the combustion process...either lean as hell, or retarded (lol pardon the pun))

[wrxhoon]

thats way u do it with a timing light then u know exacly what u r doing . so u set to specs 1 st then u play around with it depends on the fuel u use

[Mildman]

Maybe I should learn how to use one then....

A cross thread thanks,

[wrxhoon]

not hard to use but hard to get a cheap one for the skyline .

u connect the timing light to battery then the other wire u have to connect to no 1 spark plug ( thats the hard bit u have to take the coil off and put the wire between the spark plug and the coil pack make sure spark want jump across to rocker cover ) then u start the engine point the light on the crank pulley where the timing marks are press the trigger the light will now flash every time no 1 fires and u'll see the timing mark then adjust it to suit .

u can bye cheap timing lights from auto shops but u may have to modify to fit it to u r skyline .

[Guest R33GTS25T]

not nessesary no need to remove the coil at all just take off the centre plastic plate and connect the timming light to the wire loom comming from the top of the coil

[wrxhoon]

r33gt , true if u have a profesional timing light that u just atouch it to the outside of wire , most cheap ones dont pick up unlees u actualy touch the naked wire .